1. Field of the Invention
The present invention relates generally to a high efficiency gas concentrating apparatus and a method of controlling the same. The apparatus can remove and discharge nitrogen adsorbed in one of a pair of adsorption towers using a minimum amount of high purity oxygen concentrated in the other adsorption towers.
2. Description of the Related Art
Generally, a gas concentrating apparatus is configured to achieve only upper or lower equalization for first and second adsorption towers. A process for concentrating oxygen and a process for removing and discharging adsorbed nitrogen are alternately performed in the first and second adsorption towers.
Because the time taken per a half-cycle of one of the adsorption towers in the gar concentrating apparatus, where the oxygen is concentrated, is long, the operational energy of an air compressor increases, and thus the discharge noise of the nitrogen out of the second adsorption tower increases. Specifically, in order to discharge the nitrogen adsorbed in the second adsorption tower, the high purity oxygen is continuously supplied from the first adsorption tower to the second adsorption tower through an orifice that is optimized for a maximum amount of the high purity oxygen. At this point, if the oxygen is quantitatively produced, problems are not incurred because the amount of the high purity oxygen used for removing and discharging the adsorbed nitrogen is proportional to the amount of the oxygen produced.
However, for example, in the case of a portable gas concentrating apparatus, there is a need to actively control an amount of compressed air by adjusting the RPM (Revolution Per Minute) of the compressed air as much as the amount of the oxygen that is required. At this point, when the orifice is designed based on a maximum oxygen-flow rate, the concentrated oxygen may be excessively consumed to remove the nitrogen, even when only a small amount of oxygen is produced. Therefore, there is a need to implement countermeasures to this problem.